Seems the Online Docs are not for 4.0.2a as they should or generated not from the downloadable GPL version?Please explain how this difference between downloadable version and Docs could appear.

Indeed. The Online Docs are created from 4.0.4 release, available for support subscribers.

A lot of documentation fixes have gone in since the 4.0.2a release, so to provide these to everybody as soon as possible we decided to make such a trade-off.

Mostly all the code changes should in these point-releases should barely effect the docs, but this fix (making Ext.core.DomHelper simply an alias of Ext.DomHelper) turned out to have a larger effect (the Ext.DomHelper is missing in 4.0.2a).

/**
* An empty function by default, but provided so that you can perform a custom action
* after a valid drop has occurred by providing an implementation.
...
* @method afterInvalidDrop
*/
this.afterValidDrop(target, e, id);

This method is not affected by the {@link #closeAction} setting which
* only affects the action triggered when clicking the {@link #closable 'close' tool in the header}

Code:

/**
* <p>Closes the Panel. By default, this method, removes it from the DOM, {@link Ext.Component#destroy destroy}s
* the Panel object and all its descendant Components. The {@link #beforeclose beforeclose}
* event is fired before the close happens and will cancel the close action if it returns false.<p>
* <p><b>Note:</b> This method is not affected by the {@link #closeAction} setting which
* only affects the action triggered when clicking the {@link #closable 'close' tool in the header}.
* To hide the Panel without destroying it, call {@link #hide}.</p>
*/
close: function() {
if (this.fireEvent('beforeclose', this) !== false) {
this.doClose();
}
},
// private
doClose: function() {
this.fireEvent('close', this);
this[this.closeAction]();
},